Detailed Answer
Answer (B) is correct. The cost of indirect materials for 144,000 units was expected to be $180,000. Consequently, the budgeted unit cost of indirect materials is $1.25 ($180,000 ÷ 144,000). Multiplying the $1.25 unit cost times the 10,800 units actually produced results in an expected total indirect materials cost of $13,500.